Here is the full list of all 16 The Shrouded Isle achievements.
You befriended House Blackborn.
You befriended House Efferson.
In the final trial, your village forgot the virtue of Ignorance.
In the final trial, your village forgot the virtue of Fervor.
In the final trial, your village forgot the virtue of Discipline.
In the final trial, your village forgot the virtue of Penitence.
In the final trial, your village forgot the virtue of Obedience.
You have witnessed the glorious awakening of Chernobog.
You befriended House Kegnni.
You befriended House Cadwell.
You befriended House Iosefka.
You completely wiped out an entire House.
You discovered every single vice and virtue in the village.
You oversaw the transformation of a perfectly pure soul.
You wiped out the entire village.
You purified the village and witnessed the beginning of the next Age.